Investigating Childhood Leukemia in Churchill County, Nevada

BACKGROUND: Sixteen children diagnosed with acute leukemia between 1997 and 2002 lived in Churchill County, Nevada, at the time of or before their illness. Considering the county population and statewide cancer rate, fewer than two cases would be expected. OBJECTIVES: In March 2001, the Centers for Disease Control and Prevention led federal, state, and local agencies in a cross-sectional, case-comparison study to determine if ongoing environmental exposures posed a health risk to residents and to compare levels of contaminants in environmental and biologic samples collected from participating families. METHODS: Surveys with more than 500 variables were administered to 205 people in 69 families. Blood, urine, and cheek cell samples were collected and analyzed for 139 chemicals, eight viral markers, and several genetic polymorphisms. Air, water, soil, and dust samples were collected from almost 80 homes to measure more than 200 chemicals. RESULTS: The scope of this cancer cluster investigation exceeded any previous study of pediatric leukemia. Nonetheless, no exposure consistent with leukemia risk was identified. Overall, tungsten and arsenic levels in urine and water samples were significantly higher than national comparison values; however, levels were similar among case and comparison groups. CONCLUSIONS: Although the cases in this cancer cluster may in fact have a common etiology, their small number and the length of time between diagnosis and our exposure assessment lessen the ability to find an association between leukemia and environmental exposures. Given the limitations of individual cancer cluster investigations, it may prove more efficient to pool laboratory and questionnaire data from similar leukemia clusters

Comprehensive Assessment of Maize Aflatoxin Levels in Eastern Kenya, 2005–2007

Background: Aflatoxin, a potent fungal toxin, contaminates 25% of crops worldwide. Since 2004, 477 aflatoxin poisonings associated with eating contaminated maize have been documented in Eastern Kenya, with a case-fatality rate of 40%

Dietary intake, physical activity, body mass index, and childhood asthma in the Third National Health And Nutrition Survey (NHANES III)

Childhood asthma may be affected by dietary changes and increased body mass related to a sedentary lifestyle, although the mechanisms are poorly understood. To test this hypothesis, we used data from the National Health and Nutrition Survey (NHANES III) from 1988–1994, including 7,904 children. We analyzed cross-sectional information on body mass index (BMI = weight/height2), physical activity (hr/day viewing television), dietary intake (24-hr recall), and vitamin C intake (60 mg/day). The probability of self-reported asthma or wheezing relating to risk factors was calculated by logistic regression. After controlling for dietary intake, physical activity, and sociodemographic variables, asthma risk was three times higher for children aged 6–16 years in the highest percentiles of BMI (\u3e95th percentile) when compared to children in percentiles 25–49 (OR = 3.44; 95% CI, 1.49–7.96). No increase was observed in children aged 2–5 years. Low vitamin C intake was marginally related to self-reported current wheezing in children aged 6–16 years. Our results show that increased BMI may influence asthma prevalence in children, but further investigation is needed

Investigation of sex differences in hip structure in peripubertal children

CONTEXT: There is evidence that sex differences in hip structure are increased during puberty, possibly as a consequence of associated changes in body composition. OBJECTIVES: The objective of the study was to explore relationships between sex, puberty, hip structure, and body composition. DESIGN/SETTING: The design was a longitudinal birth cohort study: The Avon Longitudinal Study of Parents and Children. PARTICIPANTS: Participants included 3914 boys and girls (mean age 13.8 yr). OUTCOME MEASURES: Measures included dual-energy x-ray absorptiometry-derived femoral neck width (FNW), cortical thickness (CT), bending strength [cross-sectional moment of inertia (CSMI)], section modulus, buckling ratio (BR), and femoral neck and total hip bone mineral density. RESULTS: FNW, CT, and CSMI were higher in boys, whereas BR was lower in girls (P < 0.001). Differences in hip structure were studied according to puberty (self-completion Tanner stage questionnaires). FNW, CT, and CSMI were higher in Tanner stage IV/V vs. I/II, particularly in boys (P < 0.001, puberty-sex interaction). BR was lower in Tanner stage IV/V, particularly in girls (P = 0.008, puberty-sex interaction). Adjusting for height, fat mass, and lean mass resulted in differential attenuation in the sexes, such that CT attenuated by about 80% and about 40% in boys and girls, respectively (P = 0.004, puberty-sex interaction for adjusted CT, Tanner stages I/II vs. IV/V). The difference in BR showed little attenuation after adjustment. CONCLUSION: During puberty, hip-bending strength increases, particularly in boys, due to their greater FNW, reflecting changes in height, fat mass, and lean mass. In contrast, BR falls during puberty, particularly in girls, reflecting their smaller FNW relative to CT, involving mechanisms partly independent of height and body composition